Check if array of objects contains value from other array of objects

Question

I have following arrays of objects:

I need to check if these two arrays have the same begin property. In this case that appears to be true in three objects. So far I have tried this code, but with no luck (input.value being the first array).

const found = input.value.some((item) => item.begin === filtered.filter((time) => time.begin));

Any ideas how can I achieve this? Thank you in advance.

Answer 1

You can use simple map and findIndex method.

const found = input.value.map((item) => filtered.findIndex((time) => time.begin === item.begin) > -1).findIndex((item) => item === true) > -1;

Answer 2

You could take a Set for the beginnings of filtered and check against the set without more iterations.

Big O of this is O(n), because of O(n) of creating the set and another O(n) of the check and beacause of adding two n you get O(n).

The other approach has because of the nested structure O(n²).

const
    filteredSet = new Set(filtered.map(({ begin }) => begin)),
    found = input.value.some(({ begin }) => filteredSet.has(begin));